Among electronic devices, field-effect transistors (FET), as shown in FIG. 5, have been employed heretofore as switch elements in conventional integrated circuits. In FIG. 5, the reference numeral 12 designates an n-type silicone substrate, 13 designates a channel region, 14 designates a P.sup.+ layer, 15 designates SiO.sub.2 films, 16 designates a source electrode, 17 designates a gate electrode and 18 designates a drain electrode. The transistor function or switching function of a FET of above conventional type may be attained by controlling a gate voltage to be applied via the gate electrode 17. Namely, a number of the current carriers on the surface layer between the source electrode 16 and the drain electrode 18 is varied depending on the gate voltage to thereby control the current.
An example of a conventional rectifier element for integrated circuits has a MOS structure as shown in FIG. 6, for example, as described in an article by Hisayoshi Yanai and Yuzuru Nagata, entitled "INTEGRATED CIRCUIT ENGINEERING (1)". In FIG. 6, the reference numeral 11 designates a p-type silicon substrate, 12 designates an n-type region, 13 designates a p-type region, 14 designates an n-type region, 15 designates SiO.sub.2 films and 16 and 17 designate each an electrode. A p-n junction (i.e., a junction between the p-type region 13 and the n-type region 14) is formed between these two electrodes so as to attain rectifying characteristics.
The conventional MOS structure electronic device, being designed as described above, can be finely machined and a 256 K-bit LSI, wherein switch elements, rectifier elements or transistor elements similar in structure thereto, has been put into practical use.
In order to increase the memory capacity and the operation speed of an integrated circuit, it is essential to reduce the size of its elements per se. However, for instance, an element using Si has the limitation that, in an extremely fine pattern of the order of 0.2 .mu.m, the average free path of electrons is substantially equal to the size of the element and the independence of the element can no longer be held. Thus, it can be expected that the silicon technology developing day by day will run into a blank wall when reducing the element size. Therefore, there has been a strong demand for provision of a novel electrical circuit device which can break the technological barrier of 0.2 .mu.m mentioned above.
Under these circumstances, the present invention aims at providing an electronic device which comprises oxidation-reduction substances as materials so as to reduce the size thereof to the hyperfine molecular level.
On the other hand, a plurality of types of biogenic proteins (hereinafter referred to as electron transport proteins) having electron transport functions for carrying electrons in predetermined directions are present in vivo. For example, the electron transport biogenic proteins are embedded in biomembranes in regular orientation, to be in a specific intermolecular arrangement so that electron transport is caused between biomolecules.
The electron transport biogenic proteins show oxidation-reduction (redox) reactions in electron transport in vivo and are capable of making electrons flow from negative redox potential levels to positive redox potential levels. Hence it may be considered that the movement of the electrons can be controlled in molecular level by utilizing such properties of the electron transport proteins.
A recent study suggests that it is possible to form electron transport complexes by combining electron transport biogenic proteins with electron transport non-biogenic substances other than the electron transport biogenic proteins present in vivo.
Therefore, it may be considered that a junction having rectifying characteristics can be formed by accumulating two types of electron transport substances A and B, which are suitably selected to be different in redox potential from each other, in two layers in the form of A-B. The present inventors have completed the present invention based on this consideration.